[PATCH net v2] net: prestera: validate firmware header length

[Pengpeng Hou]

prestera_fw_hdr_parse() reads the firmware header before checking
that the firmware image contains that header.

Reject images shorter than struct prestera_fw_header before decoding the
magic and version fields.

Signed-off-by: Pengpeng Hou <pengpeng@xxxxxxxxxxx>
---
Changes since v1: https://lore.kernel.org/all/20260706092602.79240-1-pengpeng@xxxxxxxxxxx/
- target the net tree in the Subject as requested by Andrew Lunn
- rebase onto the current tree

 drivers/net/ethernet/marvell/prestera/prestera_pci.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/marvell/prestera/prestera_pci.c b/drivers/net/ethernet/marvell/prestera/prestera_pci.c
index 2989a77e3b42..1ad0e62a8433 100644
--- a/drivers/net/ethernet/marvell/prestera/prestera_pci.c
+++ b/drivers/net/ethernet/marvell/prestera/prestera_pci.c
@@ -684,6 +684,9 @@ static int prestera_fw_hdr_parse(struct prestera_fw *fw)
 	struct prestera_fw_header *hdr;
 	u32 magic;
 
+	if (fw->bin->size < sizeof(*hdr))
+		return -EINVAL;
+
 	hdr = (struct prestera_fw_header *)fw->bin->data;
 
 	magic = be32_to_cpu(hdr->magic_number);
-- 
2.50.1